Legal claims defining the scope of protection, as filed with the USPTO.
1. A method for location estimation in a wireless communication environment, comprising: at a plurality of known locations, receiving RF signals from a plurality of transmitters in the wireless communication environment to provide a site survey according to a predetermined set of metrics, the site survey characterizing the wireless communication environment by the RF signals received at the known locations; at a mobile station, receiving RF signals from the transmitters; using the RF signals received at the mobile station and based in part on the site survey, (a) calculating a number of location estimate candidates for the mobile station by a location estimation algorithm; and (b) forming a region of confidence (RoC) for the location estimate candidates.
2. The method according to claim 1 , wherein the RF signals are selected from the group consisting of cellular phone signals, WLAN signals, and Bluetooth signals.
3. The method according to claim 1 , further comprising filtering the RF signals to remove distorted signals.
4. The method according to claim 1 , wherein the location estimation algorithm for calculating the location estimate candidates is selected from the group consisting of a triangulation algorithm, a K-nearest neighbor averaging algorithm, and a smallest m-polygon algorithm.
5. The method according to claim 1 , wherein the RoC is at least a part of a circle.
6. The method according to claim 4 , wherein the center of the RoC is a location estimate determined by a location estimation algorithm.
7. The method according to claim 6 , wherein the location estimation algorithm for determining the center of the RoC is a triangulation algorithm.
8. The method according to claim 7 , wherein a first circle, a second circle and a third circle are used to determine the center of the RoC.
9. The method according to claim 8 , wherein, when the three circles intersect at six points, the center of the RoC is a centroid of a smallest triangle formed by the six points.
10. The method according to claim 9 , wherein a radius of the RoC is the longest distance between the centroid and one of the vertices of the smallest triangle.
11. The method according to claim 8 , wherein when the first and second circles intersect at two points, and the second and third circles intersect at another two points, the center of the RoC is a centroid of the smallest triangle formed by the four points.
12. The method according to claim 11 , wherein a radius of the RoC is the longest distance between the centroid and one of the vertices of the smallest triangle.
13. The method according to claim 8 , wherein when the first and second circles intersect at two points, but do not intersect with the third circle, the center of the RoC is a midpoint of the line joining the two points.
14. The method according to claim 13 , wherein a radius of the RoC is half the distance between the two points.
15. The method according to claim 6 , wherein the location estimation algorithm for determining the center of the RoC is the K-nearest neighbor averaging algorithm.
16. The method according to claim 6 , wherein the location estimation algorithm for determining the center of the RoC is the smallest M-polygon algorithm.
17. The method according to claim 1 , further comprising filtering the location estimate candidates that fall out of the RoC.
18. The method according to claim 1 , further comprising segmenting the location estimate candidates by the time it takes to obtain them, and searching for a shortest route connecting one location estimate candidate at each of the times.
19. The method according to claim 18 , further comprising searching for a shortest route according to a pair-wise algorithm.
20. The method according to claim 18 , further comprising searching for a shortest route according to a non-pair-wise algorithm.
21. The method according to claim 18 , further comprising generating a new RoC whenever the shortest route exceeds the radius of the RoC.
22. The method according to claim 1 , further comprising generating a new RoC whenever the period of the RoC expires.
23. The method according to claim 1 , further comprising generating a new RoC at a certain period of time before the period of the RoC expires.
24. A computer program product containing program code for performing the method according to claim 7 .
25. A computer program product containing program code for performing the method according to claim 15 .
26. A computer program product containing program code for performing the method according to claim 16 .
27. A computer program product containing program code for performing the method according to claim 17 .
28. A computer program product containing program code for performing the method according to claim 18 .
29. A computer program product containing program code for performing the method according to claim 21 .
30. A computer program product containing program code for performing the method according to claim 22 .
31. A computer program product containing program code for performing the method according to claim 23 .
32. A computer program product containing program code for performing the method according to claim 1 .
33. In a wireless network, a location estimation apparatus comprising: a RF signal receiver, receiving RF signals from transmitters in the wireless network; an off-line signal processor for calibrating the wireless network based on the RF signals received by the RF signal receiver at known locations and outputting the calibration data; a candidate processor, calculating a number of location estimate candidates for the RF receiver by a location estimation algorithm, using the RF signals and the calibration data; and a region of confidence (RoC) formation module, forming a RoC for the location estimate candidates using the RF signals and the calibration data.
34. The apparatus according to claim 33 , further comprising a statistical signal processor, receiving signals from the RF signal receiver and filtering distorted RF signals.
35. The apparatus according to claim 33 , further comprising a RoC filter, receiving signals from the RoC formation module and filtering bad location estimate candidates.
36. The apparatus according to claim 33 , further comprising a shortest route calculator for segmenting the location estimate candidates according to the time it takes to obtain them, and searching for a shortest route connecting one location estimate candidate at each of these times.
37. The apparatus according to claim 33 , wherein the off-line signal processor creates a location information database and updates it by storing acquired signal metrics at knows portions.
38. A wireless communication device having the apparatus according to claim 33 .
39. A handheld terminal having the apparatus according to claim 33 .
40. An access point for use in a wireless communication network, wherein the access point comprises the apparatus according to claim 33 .
Unknown
July 1, 2008
Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.